Locking device for lazy tong structures



April 25, 1939 v Dl GIACOMO ET A1. 2,156,148

LOCKING DEVICE FOR LAZY TONG STRUCTURESy Filed March -50, 1938 2 Sheets-Sheet l April 25, 1939. -v. DI GIACOMO ET Al.

LOCKING DEVICE FOR LAZY TONG STRUCTURES 2 Sheets-Sheet 2 Filed March 50, 1938 Patented Apr. 25, 1939 UNiTED STATES LOCKING DEVICE FOR LAZY TONG STRUCTURES Vincent Di Giacomo and Leoluca. Salemi, New York, N. Y.

Application March 30,

6 Claims.

This invention relates to extensible and collapsible structures and more particularly refers to improvements in such structures where two members are connected by a lazy tong connec-` tion for extension to a predetermined position which should be positively maintained.

The primary object of this invention is to provide a novel and improved arrangement for securely locking a lazy tong device in a predetermined position, so as to prevent said device from being further extended or collapsed unless the locking device is released.

Another object is to provide a locking device for a lazy tong structure which shall be particu- 5 larly adapted for us-e in connection with a c ollapsible baby chair of the type described and claimed in our patent for Collapsible baby chair, No. 2,089,090, dated August 3, 1937.

A further object is to provide, in connection with a locking device for a lazy tong structure such as used in a collapsible baby chair of the type described and claimed in our patent above referred to, novel and improved means for releasing said looking device, making it possible to collapse the structure in an easy and convenient manner.

A still further object is to provide, in connection with a collapsible structureV of the type exemplified by a collapsible baby chair as described and claimed in our patent above referred to, where two members are connected by two spaced extensible and collapsible lazy tong connections, a positive locking device for holding each lazy tong connection in a predetermined extended :z5 position and easily operable means for releasing said locking devices, said releasing means also establishing a condition whereby the two lazy tong connections will be simultaneously urged to their collapsed position in order to insure a 40 smooth and rapid setting of the baby'chair to its closed or collapsed position.

Other objects and advantages of the present invention will more fully appear as the'description proceeds and will be set forth and claimed in the appended claims.

Our invention is illustrated by Way of example in the accompanying drawings, in which:

Fig. l is a plan view of a collapsible baby chair, embodying one embodiment of our invention;

Fig. 2 is a rear view in elevation thereof;

Fig. 3 is a side view in elevation of the same in its extended condition, ready for use;

Fig. 4 is a side view in elevation showing the device in use, placed and secured upon an ordinary chair;

1938, Serial No. 198,964

Fig. 5 is a det-ail side view in elevation in an enlarged scale of the sliding connection between one of the arms of the lazy tong structure at one side of the collapsible chair and the bottom board of said chair; i

Fig. 6 is a plan view thereof with parts partly broken away;

Fig. 7 is an end view in elevation of the same as seen from line 'I--T of Fig. 5;

Fig. 8 is an end view in elevation of the same from the opposite end as seen from line 8--8 of Fig. 5; and

Fig. 9 is a vertical cross section of the same through line 9--9 of Fig. 5.

The collapsible baby chair illustrated oomprises a relatively shallow open bottom rectangular c-asing I0, the topy of which II is provided with an opening I2 Wide -enough to permit the body of a small child to be inserted therethrough.

Opening i2 is normally closed by a lid I3 hinged to its rear edge as shown at I4, I5 and retained in its closed position, where it is flush with the top I I, by a suitable locking device, such as for instance shown at I6.

'Ihe device also comprises a bottom board I lI, the outline of which corresponds to the outline of the c-asing, said board being adapted to rest against the open bottom of said casing as shown in Fig. 2, forming a closure therefor when the device is in its contracted position.

The bottom board I'I is secured in position of abutment against the lower edge of the casing by some suitable releasable means. Each end wall of the casing is shown provided with a pivotally mounted hook I8, adapted to engage a stud I9, secured to the edge of the bottom board.

The bottom board is connected to the casing by a lazy tong system comprising two articulated cross arms 22, 23, at each end of the structure. Said two arms are pivotally connected to each other -at their central point 24. The rear end of arm 22 is pivotally connected to the rear of the casing as shown at 25, said connection being preferably effected through the intermediary of a bracket 26. 5

In a similar manner the rear end of arm 23 4 is pivotally connected at 2l to an angle bracket 28 upwardly projecting from the bottom board I? in proximity to the rear of its corresponding end. The front ends of said arms 22, 23 are slidably' and pivotally connected to the front part of bottom board Il' and casing I0 respectively, in order to permit the articulated structure formed by each set of cross arms to contract or expand' with the casing and bottom board structure. 55

To this end the front part of the lower surface of top H of the casing is provided, in proximity of each end, with an angle bracket 29 having a vertical depending rib 36, the inner surface of which is substantially on the same plane as the outer surface of its corresponding arm 23. Said rib 38 is provided with an elongated vslot 3l, eX- tending in a front to rear direction, within which can slide a stud 32 carried by and laterally projecting from the front end of arm 23, the same establishing a sliding and pivotal connection between rib 38 and arm 23.

In a similar manner the front part of bottom board l1 is provided at each end with an angle bracket 33 having a rib 34 vertically extending therefrom in a front to rear direction. Said rib is provided with an elongated slot 35 within which is inserted a stud 36 carried by and laterally extending from the front end of arm 22.

In the arrangement described in our previous patent above referred to, the device was retained in its extended position, shown in Fig. 3, by causing the stud 36 to engage a notch provided at the rear end of slot 35, said notch forming a stop for the lazy tong structure preventing its being collapsed until the lower end of arm 22 was forced upwardly by hand so as to disengage its stud 36 from said notch and reset said stud 35 in the runway formed by slot 35.

However, in actual practice we have found this manner of retaining the device in its extended position somewhat insecure because even a slight movement of the baby within the chair is likely to cause stud 36 to become disengaged from the notch and slide along slot 35 of its own accord, the stability of the structure thus being destroyed. We have also found that such an occurrence would take place at times during the manipulations necessary for setting the chair in position, one or the other of arms 22 becoming disengaged and causing the lazy tong structure at the corresponding side to spread and the entire structure to be set askew, requiring some time and maneuvering in order to set it in the proper position.

We have accordingly sought to remedy this condition by providing means of an absolutely positive character for locking the lazy tong structures in their extended position.

In the embodiment of our invention illustrated in Figs. l to 9, said locking means are designed for automatic locking action and for release by the manipulation of two conveniently placed depressible levers. Furthermore, in order to insure ready and simultaneous action of the two lazy tong structures in collapsing the chair we also provide means whereby the operation of said depressible levers will cause a force to be exerted against the arms 22, urging said arms to move in the collapsing direction with their respective stud 36 sliding along the corresponding slot 35. The locking and releasing device to which the present invention is mainly directed is illustrated in detail in Figs. 5 to 9. In the same it will be seen that when the lazy tong structure is in its extended position and when stud 36 of arm 22 has reached the rearward end. of slot 35, said arm 22 will be securely retained in said position by a pin 31 passing through a corresponding opening at the lower end of arm 22, said pin penetrating an opening 38 provided in rib 34.

Said pin 31 is carried by a leaf spring 39 lying flat against the side surface of arm 22 and having its inner end 46 secured to said arm, as shown at 4l, the other end carrying pin 31 being free to be iiexed outwardly about the fixed end 40, so as to cause pin 31 to become disengaged from opening 38 in rib 34.

Y Spring 36 can be actuated by means of a button 42 and it is obvious that when said spring is deflected outwardly a distance sufficient to cause pin 31 to become disengaged from opening 38, stud 36 will be free to slide forward along slot 35.

In a simpler embodiment of our invention the parts so far described are sufficient to provide the required positive locking action and means for effecting the release of the arms 22 by hand, Without any additional parts being required. However, we have found that if the releasing action is effected by means of a depressible lever,

having its depressible portion extended towards the front of the bottom board I1, a speedier and easier operation can be effected. To this end, we form the button 42 with a stem 43 and a head 44 of a diameter larger than said stem, the space between the inner surface of the head and the outer surface of spring 39 forming a runway for the cam shaped rear end 45 of a depressible lever 46.

Said lever is pivotally mounted at 41 against the inner side of rib 34 and is normally maintained in the position shown in Fig. 5 where its front depressible portion 48 is caused to remain vertically spaced from the upper surface of the base board I1 by a leaf spring 49. The rear end of said lever is laterally bent across the plane of rib 34, as shown at 58, and is then bent upwardly and inwardly as shown at 5l-52, its free end 52 being in the same plane as the clearance space between head 44 and spring 39 and registering with said space.

The outline ofh said cam portion 5I-52, seen from the side, `is an arc of a circle having for its center pivot 41.

It follows that when the front end 48 of said lever 46 is depressed, the outward bend of its rear end 5I-52 will gradually flex spring 39 outwardly to the point where pin 31 will become disengaged from opening 38, the upper part of the chair structure being then free to collapse by virtue of its own weight.

We have found that it is of advantage to provide some means urging arms 22 in the collapsing direction so as to supplement the action of gravity because it frequently happens that when the device is allowed to collapse by the action of its own weight one side may be depressed more than the other, causing the corresponding lazy tong structure to jam. We, therefore, prefer to add to the locking and releasing device just described means actuated by said device insuring a positive and simultaneous collapsing action of the two arms 22.

Said means are represented in the drawings by an arm 53, pivotally mounted at 54 against the inner surface of rib 34, said arm bearing against the extension 55 of stud 36 when said stud is at the rear end of slot 35. At the other end of rib 34 is pivotally mounted at 56 a crank lever 51, having an upwardly extending arm 58 connected by a tension spring 53 to arm 53, and having a forwardly extending arm 66 provided Vwith a laterally extending pin 6I, projecting between the under surface of front end 48 of lever 46 and spring 49.

By virtue of this arrangement, it will be seen that when part 48 of lever 46 is depressed, crank lever 51 will be angularly displaced ina counterclockwise direction with respect to Fig. 5, and

spring 59 will exert a pull upon arm 53. When the pressure against part 43 is released spring 49 will force said part 48 upwardly and at the same time it will return crank lever 51 to its normal position. v

Arms 58 and 53 are preferably joined by a lost motion connecting bar 52, pivotally connected at 53 to the end of arm 58, and being provided at the other end with a slot 64 engaging pin 65 of arm 53.

Slot Se is so arranged as to permit a lost motion to take place between it and arm 53 when part 138 of lever 5B is depressed, causing an increase in the tension of spring 59. This increase is due to the fact that armv 53 will bear against extension 55 of stud 35 until the angular movement of lever 46 will have been suicient to cause pin 31 to become disengaged from opening 38. At such time the lower end of arm 22 will be free to move forward, its stud 3B sliding along slot 35, and the tension stored in 'each spring 59 Will cause the corresponding arm 53 to force stud 36 forward. Furthermore, since both springs 59 are under tension, both studs 36 will be pressed forward at the same time and a simultaneous collapsing action of the two lazy tong structures will, therefore take place.

It is thus seen that by providing a relatively simple and inexpensive arrangement we insure a positive locking of the chair in its extended position and an easy release thereof from such position, and we also insure a condition whereby the collapsing of the chair will take place evenly and without jamming.

The constructional details of our invention can vary from those shown without departing from the inventive idea. The drawings should, therefore, be understood as being intended for illustrative purposes only and not in a limiting sense.

Accordingly, we reserve the right to carry our invention into practice in all those ways and manners which may enter, fairly, into the scope of the appended claims.

We claim:

1. In a lazy tong structure comprising a platelike base member, a top member, a pair of pivotally connected cross arms interposed therebetween at each side thereof, one end cf each arm being pivotally connected to one of said members, a slotted bracket at each side of each member, pivotally and slidably connected to the other end of each arm, and means for locking said structure in a predetermined extended position, said means comprising a spring actuated pin carried by one of the pivotally and slidably connected arms of each pair of crossed arms, the corresponding bracket having an opening adapted to receive and interlock with said pin when the structure reaches said predetermined extended position, and means to release said pin from interlocking engagement with said bracket.

2. In a lazy tong structure comprising a platelike base member, a top member, a pair of pivotally connected cross arms interposed therebetween at each side thereof, one end of each arm being pivotally connected to one of said members, a slotted bracket at each side of each member, pivotally and slidably connected to the other end of each arm, and means for locking said structure in a predetermined extended position, said means comprising a leaf spring carried by one of the pivotally and slidably connected arms of each pair of crossed arms, a pin carried by said spring, projecting through said arm, the corresponding bracket having an opening adapted to receive and interlock with said pin when the structure reaches said predetermined extended position, and means to ex said spring to Withdraw said pin from said opening.

3. In a lazy tong structure comprising a platelike base member, a top member, a pair of pivotally connected cross arms interposed therebetween at each side thereof, one end of each arm being pivotally connected to one of said members, a slotted bracket at each side of each member, pivotally and slidably connected to the other end of each arm, and means for locking said structure in a predetermined extended position, said means comprising a leaf spring carried by one of the pivotally and slidably connected arms of each pair of crossed arms, a pin carried by said spring, projecting through said arm, the corresponding bracket having an opening adapted to receive and interlock with said pin when the structure reaches said predetermined extended position, and a tiltable lever pivotally mounted on said last mentioned bracket, said lever having a cam-acting extension engaging means on said spring, whereby said spring will be flexed to Withdraw said pin from said opening when said lever is tilted in a given direction.

4. In a lazy tong structure comprising a platelike base member, a top member, a pair of pivotally connected cross arms interposed therebetween at each side thereof, one end of each arm being pivotally connected to one of said members, a slotted bracket at each side of each member, a stud carried by the other end of each arm, extending through the slot in the corresponding bracket, pivotally and slidably connecting said arm to said bracket, means for locking said structure in a predetermined extended position, said means comprising a leaf spring carried by one of the pivotally and slidably connected arms of each pair of crossed arms, a pin carried by said spring, projecting through said arm, the corresponding bracket having an opening adapted to receive and interlock with said pin when the structure reaches said predetermined extended position, and a tiltable lever pivotally mounted on said last mentioned bracket, said lever having a cam-acting extension engaging means on said spring, whereby said spring will be flexed to withdraw said pin from said opening when said lever is tilted in a given direction, a pressure arm pivotally mounted on said bracket bearing against the corresponding stud to urge it in the colapsing direction, a tension spring having one end attached to said pressure arm, and a movable tensioning lever, also pivotally mounted on said bracket, to which is attached the other end of said spring, said tensioning lever having a projection in the path of and engaged by said tiltable lever when said tiltable lever is tilted in the pin withdrawing direction, whereby power will be stored in said spring while said pin is being withdrawn from the opening in said bracket, so as to force said corresponding pivotally and slidably connected arm in the collapsing direction.

5. In a lazy tong structure comprising a platelike base member, a top member, a pair of pivotally connected cross arms interposed therebetween at each side thereof, one end of each arm being pivotally connected to one of said members, a Slotted bracket at each side of each member, pivotally and slidably connected to the other end of each arm, and means for locking said structure in a predetermined extended position, said means comprising a spring actuated direction.

6. In a lazy tong structure comprising a platelike base member, a top member, a pair of pivotally connected cross arms interposed therebetween at each side thereof, one end oi each arm being pivctally connected to one of said members, a slotted bracket at each side of each member, pivotally and slidably connected to the other end of each arm, and means for locking said structure in a predetermined extended position,

said means comprising a leaf spring carried by one of the pivotally and slidably connected arms of each pair of crossed arms, a pin carried by said spring, projecting through said arm, the corresponding bracket having an opening adapted to receive and interlock with said pin when the structure reaches said predetermined eX- tended position, a tiltable lever pivotally mounted on said last mentioned bracket, said lever having a cam-acting extension engaging means on said spring, whereby said spring will be flexed to Withdraw said pin from said opening when said lever is tilted in a Vgiven direction, and spring means urging said last named pivotally and slidably connected arms in the collapsing direction when said pin has been withdrawn from said opening.

VINCENT DI GIACOMO. LEOLUCA SALEMI. 

